Method of manufacturing grids for use in electric discharge tubes



Sept. 3, 1963 w. BEX ETAL 3,102,560

METHOD OF MANUFACTURING GRIDS FOR USE IN ELECTRIC DISCHARGE TUBES FiledNov. 10, 1953 2 Sheets-Sheet 1 llllllllllllllll J 28 I -i. I 9 I :5 445:04. Q INVENTOR.

WILHELMUS BEX GERRIT STARRE BY A 2 z AG-E/Vr Sept. 3, 1963 w. BEX ETALMETHOD OF MANUFACTURING GRIDS FOR USE IN ELECTRIC DISCHARGE TUBES 2Sheets-Sheet 2 Filed Nov. 10, 1953 I I l /////////////l///////I//////////////ll/II/I/47/4 7// Ill. Illllll 7////////////-Il/l/l///m//////////////6m W// INVENTOR. WIL HELMUS B EX GERRIT 5 TARRE I///////////A// /4/////IV. r//////////////I//l//// 3,102,560 METHUDF MANUFAQTURING GRIDS FUR USE IN ELECTRIC DISCHARGE TUBES Wilhelmus Boxand Gerrit Starre, Eindhoven, Netherlands, assignors, by mesneassignments, to North American Philips Company, inc, New York, Nil! acorporation of Delaware Filed Nov. 10, 1953, Scr. No. 391,278 (Ilairnspriority, application Netherlands Nov. it}, 1952 Claims. (Cl. Mil-71.5)

The invention relates to a method of manufacturing grids for use inelectric discharge tubes. The grids comprise at least two grid backbonesand a wire wound about them, the wire being introduced into grooves inthe backbones and secured therein. The aforesaid plurality of grids arewound on common grid backbones and then separated from one another.

It is known to wind a plurality of successive grids on two gridbackbones. in this known method the grid backbones are drawn along witha greater speed after a grid has been wound than during the winding of agrid, the wire being wound about the backbones. during the intermediateperiod so that the grid wire between two grids is Wound with greaterpitch about the backbones than in the grid itself. This known method hasa limitation in that the who between two grids is. not utilizedeficctively. Since this wire which may have a thickness of 4011. iscomparatively costly, the loss due to the wire portions between thegrids is comparatively great. The invention has for one of its objectsto provide a method in which loss of wire does not occur or occurs to .aconsiderably smaller extent than in the grid-winding machines hithertoknown.

The method according to the invention has another feature that after agrid has been wound for the desired length the supply or wire to thebackbones ceases so that the wire breaks oli. After this breaking-offthe end of the wire is secured to the backbone at a certain distancefrom the first grid and a new grid is wound. Consequently, in thismethod the wire between two successive grids is absent.

In one embodiment of the invention, the wire issecured into a groove ofthe backbone immediately after the introduction of said wire into saidgroove.

In 'a further embodiment of the present invention the portion of thewire extending beyond the fastening area of the wire to the gridbackbone is burned off.

The device for carrying out one of the aforesaid methods comprises oneor more supply coils for the grid backbones which are slidable in commonalong a mandril in their direction of length and a supply coil for thewire which is fed through a wire guide to the grid backbones,

the wire guide rotating relatively to the grid backbones and has thefeature that provision is made of a mechanism by means of which the wiresupply stops each time after one grid has been wound.

In a further embodiment of the invention the wire guide rotates aboutthe grid backbones.

In a further embodiment of the invention the device comprises a cuttingtool and a hanging tool for cutting and hanging down grooves in the grid:b-aclcbones respectively. It is in general desirable that the linebetween the centre B and the tangential point of the cutting tool and agrid backbone and the line between the centreand the tangential point ofthe hanging tool and a grid backbone should be at an angle of less than180 to one another,

@f'ice l atented Sept. 3, 1963 the means for guiding the wire to thebackbones lying inside this angle. The cutting tool and the hanging toolmay, in this case, be constituted by rollers or by knifeshaped elements.

in order that the invention may be readily carried in effect, it willnow be described with reference to the accompanying drawing which showsdiagrammatically one embodiment of the grid-winding machine according tothe invention.

FIG. 1 shows the grid-winding machine and FIG. 2 shows, on an enlargedscale, grid backbones having a grid manufactured by means of the windingmachine according to the invention before one of the wire ends has beenburned off and FIG. 3 shows grid backbones, at which the wire ends ofthe grids have been removed.

FIGS. 4, 5, 6 and 7 are a few sectional views of the winding head of themachine on an enlarged scale.

FIGS. 8 and 9 show two different positions of the cutting tool and thefianging tool relative to the grid backbones.

Referring to FIG. 1, reference numeral 1 designates the ed of thegrid-winding machine, along which the sledge 2. to which the ends of thegrid backbones are secured is displaceable. For this purpose thestructure is provided with a wire rod 3, which is rotated by means of aset of gear wheels 4 and 5, which may, if desired, be replaced byothers. Thus the sledge 2 is moved with the desired speed along the bedof the grid-winding machine. The gear wheel 5' is seated on the shaft 6,the number of revolutions of which is derived from the stationary head7. This stationary head comprises a rotatable housing 8 in which arearranged the tools for introducing and securing the wire into and to thegrid backbones respectively. This housing comprises a cutting tool 9 anda hanging tool 1%, the operations of which will be explained more fullywith reference to FIGS. 4, 5, 6, 8 and 9. The housing 8 rotates aboutthe grid backbones 11, which move only owing to the motion of the sledge2 in the direction of length of the machine, but which do not perform arotary movement.

During the displacement, the grid backbones are wound off a supply coil12.

The machine comprises, moreover, a burning-oil device 13, the operationof which will be explained hereinafter. The structure of the machine isfurther-more provided with a plurality of gear wheels 14,15 and 16, bymeans of which the shaft 6 and the housing 8 are rotated from a primemover (not shown). On this side are furthermore provided a plurality oflug discs and tumblers by means of which various tools which will bedescribed hereinafter are governed.

FIG. 2 shows a grid obtained by the method according to the inventionwith the use of the device according to the invention before the end ofthe wire has been burned off. The grid backbones 2d and 21 are providedwith grooves 22 by the roller 9. The wire 23 is wound in these grooves,after which the grooves containing the wire are closed by hanging bymeans of the hanging roller 10'. In the devices hitherto known thesledge comprising the grid backbones is moved more rapidly after a gridhas been wound while the winding operation'is continued so that betweentwo grids the pitch of the wound wire is. materially greater. Afterwardsthis intermediate portion must be rcmoved.

According to the invention the wire is broken off as soon as the gridhas attained the desired length. For manufacturing a grid the end of thewire is secured again to the grid backbones so that loss of wire isavoided. When the grid wire is secured to the grid backbones, a portionoat this. wire extends beyond the backbone,as is shown in FIG. 2. Thisend 24 is then burned so that grids as shown in FIG. 3 are obtained.

FIGS. 4, 5 and 6 show the tools for carrying out the method describedabove on an enlarged scale.

In the housing ii the cutting tool 9 is constructed in the form of acutting roller and a fianging tool lit in the fiorm of a flangingroller. The cutting roller 9 is seated on an arm 25, which is adapted torotate about the point 26 of the housing 8. Similarly the flangingroller is seated on an 27, which is also adapted to rotate about thepoint 26. The two rollers are drawn to one another by the spring 2 8 andthe two arms are provided with stops 29 and 30 between which provisionis made of a key 31 with the aid of which the arms 25 and 27 are movedfrom one another by axial displacement, the rollers 9 and It beinglifted from the grid backbones. The key 311, shown in FIG. 7 is movablein an axial direction by means of a lug disc and a lever, provided onthe front side of the machine. The two rollers are not positioneddiametrically opposite one another, but the lines from the point 32,about which the housing 8 rotates, to the tangential points of thecutting roller and the fianging roller with a gridbackbone are at anobtuse angle to one another, as is shown in FIGS. 8 and 9 on an enlargedscale.

The housing 3 is, furthermore, provided with a supply coil 33 (for thewire 34. This wire moves over a roller 35 along a stud 36 of an arm 37.The wire moves between the arm '37 and the lever 38, which is adapted torotate about a fixpoint 39 and is moved by the displacement of the point40. This displacement may also be produced by means of a lug and atumbling lever on the front side of the machine. The angle x in whichthe stud 36 is located is smaller than 180.

The device comprises, moreover, the burning-01f device 13, to whichelectric current is supplied periodically.

The device operates as follows: While the housing 8 rotates with thetools contained therein, the cutting roller 9 and the flanging roller 10engage the grid backbones 120 and '21 for a certain period. The cuttingroller cuts a groove in each of the grid backbones, the grooves in eachbackbone being spaced apart from one another by a distance varying withthe displacement of the grid backbones. Simultaneously the wire 34' iswound on the grid, alter which each groove is closed by fianging by theHanging roller 10. The wire is wound oil the supply coil 33'. When thegrid has attained the desired length, the lever 38 rotates about thepoint 3 9 in a manner such that the wire is clamped tight between thelever 37 and the lever 38. This operation is controlled by means of V alug and a tumbling lever on the front side of the machine. Owing to theclamping of the wire, it breaks oil, the breakage taking place at thefastening area of the wire to the grid backbone. Substantiallysimultaneously the key 31 is moved in an axial direction in a mannersuch that the rollers 9 and 1d are lifted from the grid backbones. Atthe same time the grid backbones may if desired be displaced morerapidly. The wire breaks off at a position or the rollers relative tothe grid backbones as is shown in FIG. 8. It is assumed in this case forthe sake of simplicity that the rollers are stationary While the gridbackbones rotate. However, in reality, the rollers rotate and the gridbackbones are stationary. When the rollers 9 and to are lifted firo-mthe grid backbones, the latter are displaced more rapidly by means ofthe sledge 2, the end 24 of the grid wire being adapted to move over thegrid backbones without being wound thereon since the end is not securedin a groove by flan ing. After the grid backbones have been displacedover a desired distance so that the distance between two successivegrids is sufliciently large, the rollers 9 and 10 are again moved toengage the grid backbones by the displacement of the key 31, after whichgrooves are again out and closed by flanging. In the positions of thegrid backbones relative to the rollers shown in FIG. 9 the end of thewire is grasped by the flanging roller and secured to the grid backboneso that the wire is rewound about the grid backbone. After a grid of thedesired length has been wound the wire is again broken oh" and thebackbones are again moved more rapidly over a certain distance. Duringthis operation the end 24 of the grid passes by the burningbtf device d3to which electric current is supplied at this instant so that the end2-4 of the wire is burned oil. it is of importance that the cutting tooland the fianging tool should not be simultaneously in contact with agrid backbone.

While we have shown and described the preferred embodiment of ourinvention, it will be understood that the latter may be embodiedotherwise than as herein specifically illustrated or described and thatin the illustrated embodiment certain changes in the details ofconstruction and in the arrangement of parts may be made withoutdeparting from the underlying idea or principle of the invention withinthe scope of the appended claims.

What is claimed is:

1. A device for automatically manufacturing a plurality of separategrids on common grid backbones comprising at least one supply coil, atleast two parallel, spaced grid backbones, means for winding the wire ofsaid coil about said grid backbones including a wire guide which rotatesrelatively to said grid backbones and feeds Wire from said supply coilto said grid backbones, said wire guide including an arm, a leveradapted to rotate about a fixed point to periodically clamp said Wireagainst said arm and break ofit the supply of wire to said grid, andmeans securing the free end of the Wire to said grid backbones at adistance spaced from the previous grid.

2. A device as set forth in claim 1 wherein said wire guide rotatesabout said grid backbones.

3. A'device as set forth in claim 1 further comprising means for burningoff the free ends of the wire of said supply coil on said gn'd backbonesafter said wire has been wound thereon 4. A device for automaticallymanufacturing a plurality of separate grids on common backbones oomprising at least one supply coil, at least two parallel, spaced gridbackbones, means for winding the wire of said coil about said gridbackbones including a wire guide which rotates relatively to said gridbackbones and feeds wire from said supply coil to said grid backbones,said wire guide including an arm, a lever adapted to rotate about afixed point to periodically clamp said wire against said arm and breakoff the supply of wire to said grid, and means for securing the free endof the wire to said grid backbones at a distance spaced from theprevious grid, a cutting tool for cutting grooves, a fianging tool forclosing said grooves by hanging after said wire has been insertedtherein, said cutting tool and said fiangin-g tool being adapted torotate about said grid backbones and relative to the center of rotationabout said grid backbones, the line between said center of rotation andI the tangential point of said cutting tool and a grid backbone and theline between said center of rotation and the tangential point of saidhanging tool and a grid backbone are at an angle of less than and saidwire guide being located inside said angle, means for moving both saidcutting tool and said Hanging tool in a direction away from said gridbackbones upon the breaking-off of said wire.

5. A device for automatically manufacturing a plurality of separategrids on common grid backbones for use in electric discharge tubescomprising at least one supply coil, at least two parallel, spaced gridbackbones, means for winding the wire of said coil about and on saidgrid backbones, means for stopping the winding of 5 said wire on saidgrid backbones, means fur severing said win-e afiter a pmedetemminedLength of wire has been wound on said gziid backbones, and means forconnecting said wire again to said grid backbones at spaoed intervalsthereof order to another giid on said backbones.

References Cited in the file of this patent UNITED STATES PATENTS1,970,599 Franke Aug. 21, 1934 1,994,307 FLI'EUWS Mar. 12, 19352,181,288 Washblml NOV. 28, 1939

1. A DEVICE FOR AUTOMATICALLY MANUFACTURING A PLURALITY OF SEPARATEGRIDS ON COMMON GRID BACKBONES COMPRISING AT LEAST ONE SUPPLY COIL, ATLEAST TWO PARALLEL, SPACED GRID BACKBONES, MEANS FOR WINDING THE WIRE OFSAID COIL ABOUT SAID GRID BACKBONES INCLUDING A WIRE GUIDE WHICH ROTATESRELATIVELY TO SAID GRID BACKBONES AND FEEDS WIRE FROM SAID SUPPLY COILTO SAID GRID BACKBONES, SAID WIRE GUIDE INCLUDING AN ARM, A LEVERADAPTED TO ROTATE ABOUT A FIXED POINT TO PERIODICALLY CLAMP SAID WIREAGAINST SAID ARM AND BREAK OFF THE SUPPLY OF WIRE TO SAID GRID, ANDMEANS SECURING THE FREE END OF THE WIRE TO SAID GRID BACKBONES AT ADISTANCE SPACED FROM THE PREVIOUS GRID.